An electrical power converter of an electric vehicle is provided with a smoothing capacitor for smoothing an input/output voltage. In the electrical power converter provided with the smoothing capacitor, an electric charge that is accumulated in the smoothing capacitor needs to be discharged when an electrical system of the electric vehicle is stopped. A discharge resistance is often provided in the electrical power converter as one of the methods for discharging the electric charge. During a normal operation of the electrical system of the electric vehicle having the electrical power converter provided with the discharge resistance, a small amount of current flows in the discharge resistance, and consequently the discharge resistance generates heat. Heating the smoothing capacitor by the heat of the discharge resistance deteriorates the properties of the smoothing capacitor. Therefore, there has conventionally been developed a technology for protecting the smoothing capacitor from the heat of the discharge resistance.
Japanese Patent Application Publication No. 2008-211129 discloses a structure of an electrical power converter provided with a smoothing capacitor and a discharge resistance, wherein the smoothing capacitor is not easily heated by the heat generated by the discharge resistance.